1. Field of the Invention.
This invention pertains to tool holders, and more particularly to holders for tools employed to cut insulated electrical conductors.
2. Background of the Invention.
Various equipment has been designed to process individual pieces of insulated electrical conductor cut from an endless supply thereof. Examples of such equipment are discussed in U.S. Pat. Nos. 3,309,948; 3,527,124; 3,857,306; and 3,913,426. U.S. Pat. No. 4,317,391 shows an insulated conductor cutting and stripping machine wherein the cutting blades are secured to reciprocating slides by means of blade clamps. The cutting blades are positionable longitudinally with respect to the conductor to be cut by a dovetail arrangement.
A well-known machine for cutting a supply of conductor into relatively short lengths is the Model CS-9AT machine manufactured by Artos Engineering Company of New Berlin, Wis. Referring to FIG. 1 of the drawings, that machine is depicted schematically at reference numeral 1. Reference numeral 3 indicates a reel that holds a very long length of conductor 5. The conductor 5 from the reel 3 is fed horizontally in the direction of arrow 7 by a suitable mechanism, not shown. Reference numeral 9 indicates schematically a pair of substantially identical tool holders. The tool holders 9 reciprocate horizontally, as indicated by arrow 45, such that cutting blades 11 and 13 cooperate to sever the endless conductor into shorter pieces 15 of desired length, as is known. The severed pieces of conductor 15 are secured by clamps 18 onto a double track conveyor 17 that transports the pieces to other stations for further processing. The direction of conveyor 17, as indicated by arrow 19, is perpendicular to the direction 7 of the wire.
An important consideration in the design of an insulated conductor cutting machine is that the cut pieces 15 must be free to move unobstruced past the tool holders 9 onto the conveyor 17 as it is indexed. Specifically, it is essential that the trailing ends 33 of the pieces 15 do not strike any portion of the machine 1, including the tool holders, because that would cause the cut pieces to skew on the conveyor and cause problems at downstream processing stations. Accordingly, it is known to place the blades 11 and 13 at the extreme ends of the tool holders. Referring to FIG. 2, the construction of a conventional tool holder is shown in detail. The cutting blades 11 and 13 form the outer boundaries of the tool holders and machine, and they also define the boundary of the path of the cut piece 15 through the machine.
Each tool holder 9 includes a bracket 21 that is mounted for reciprocation on the machine by well-known means. The bracket 21 is manufactured with a pair of opposed faces 23. Between the faces 23 are inserted a number of spacers 25 and a leg 27 of a blade holder 29. The required placement of the blade 13 results in a blade holder 29 designed with a generally Z-shape. The spacers 25 and blade holder 29 are held firmly in place by set screws 31. The longitudinal position of the blade 13 is adjustable by interchanging the leg 27 with any of the spacers. The blade 13 is secured to the outer leg 35 of the blade holder by one or more screws 37 that are threaded into tapped holes 39 of the blade 13. Thus, the blade 13 forms the outer boundary of any portion of the machine that could lie within the path of the ends 33 of the cut pieces 15.
Although the prior tool holder 9 has had some commercial success, it nevertheless has several deficiencies. One shortcoming is that it is very expensive to provide a cutting blade with the tapped holes 39. A cutting blade with the tapped holes costs about four times that of the identical blade without the tapped holes. Another disadvantage of the design of FIG. 2 is that the spacers 25 must be rearranged in relation to the leg 27 when it is necessary to change the location of the blade along the path of the wire 5. That requires the entire tool holder to be removed from the bracket for repositioning the cutting blade. Such manipulations of the cumbersome spacers and blade holder results in expensive and inconvenient machine down-time. Further, the discrete lengths of the spacers impose steps that limit the number of locations at which the blade holder can be positioned.
As mentioned, the insulated conductor cutting machine 1 must be designed such that no part of the machine is in the path of the cut pieces, particularly trailing ends 33. Neither the tool holder nor the machine described in U.S. Pat. No. 4,317,391 meet those criteria.
Thus, a need exists for a tool holder for an insulated conductor cutting machine that employs standard cutting blades and eliminates the positioning limitations of prior tool holders.